Thanks for the helpful input.
I just haven't been riding in anything but the hot weather for several years. I basically quit riding the last few years. I'm a little unsure what I might expect. The forecasts that I'm seeing look like the temperatures could range pretty widely.
I know I did a Gran Fondo in Aspen in 2015 in like June and the temps started out pretty chilly (40s?) so I put on leg warmers and it was a pia to have to stop just a few miles into it and pull those off. They were way too thermal. Now, I know there are some pieces that are more and less thermal.